Connecter switch



Junej24, 1930. C, ELOMAX 1,767,594`

CONNECTER SWITCH Filed sept. 21, 1927l mrsnnr lar ense E. L UmaxPatented June V24, 1930 UNITEDsrArEs OFFICE? CLARENCE E. Lor/IAX, OEvAAK PARK, ILLINOIS, AssrcNoyR 'ro REsERvE'r-IOLDING rCoM- PANY, 0ExANsAs CITY, MISSOURI, A CORPORATION OE DELAWARE CONNECTER swI'rcI-rApplication led September 21, 1927,. .Serial No. 2$3,953.

This invention relates kin general to automatic switches for telephonesystems, and the object of the inventionis the provision of a new andimproved'co'nnecter switch.

Heretofore it has been found in practice that the applicationof ringingvcurrent to the line conductors ofthecalled line `often causes the linerelay associated with the lineswitch of the called line to operate be-Aforey the cut-oit relay of .the lineswitch has had time to disconnectthe line relay.

The main object of the present invention is the provision ofk animprovedcircuit arrangement in a connecter switch for delaying-theapplication of ringing currentto the line conductors of the called lineuntil the cut-off relay of the called linehas had time to operate anddisconnect the line relay. kThis is accomplished by the addi- 29 tion ofa ringing relay which energizesl in order to connect ringing current tothe called line afterA the switching relay has operated. Incidentallythis permitsa ,number of springs heretofore operated by the switchingrelay to be voperated by the ringing relay. y

Another feature of the present invention .relates tothe novel circuitarrangements in the connecter switch for-"connecting dial Y 30 tone tothe calling line after a (connecter l switch is seized by thelineswitclrof a calling line.- The dial tone is provided to inform thecalling subscriber 'that `he may proceed with the dialling operation tocomplete the desired connection. Y

Referring now to the drawings, there is shown by means of the usualcircuit diagrams the new and improved connecter switch H, a rotarylineswitch LS, andan 40 individual subscribers lsubstation A. Y

The connecter switch His of the well known Strowger vertical and rotarytype and has access to automatic subscribers lines such as the lines ofsubstation A. In the V present case, vthe connecter H is yaccessiblenormal position andwhich lha'veracceL-is to' connecter vswitches such asconnecter H.

VThe substation A consists or" a calling device and the usualinstrumentalities to envablethe subscriber to carryk on conversation.The line of substation A terminates in the lineswitch LS and connecterbank contacts in connecterssuch as .connecter f Y Withthis generaldescription of the drawings in mind, the operationof the circuits may.now be explained inr detail. For this purpose, it willbe assumed that anautomatic subscriber desires to obtain connection with subscriber A.vThe customary subscribers substation yand individuall lineswitch beingwellf understood by those skilled in the art and forming no part oi thepresent invention, it is therefore believed that it will suilicev to saythat in'response to the removal ofy the receiver by thecallingsubscriber,V his individual lineswitch seizes anv idle trunk leading toan idlefconnecter switch Vsuch as indicated bythe reference f characterH. Let us assume that the conlnecter H is the connecter seized by thecall-v ing lineswitch.v When the calling lineswitch comes to rest uponthe contacts associated with the conductors 20,21,y and 22 the switchingrelay ofthe lineswitch completes anuenergizing circuit for the linerelay. 4;'

ofthe connecter as follows: frompground by way of normally closedsprings controlledby armature 38, lower winding of line relay il,normallyr closed` springs controlled by armature 32,v conductor 21,over,

.loop `baclto conductor 20, normally closed Vsprings controlled by.armature ,31, and

and its worling'contact completes an ener-Wk gizing circuit forenergizing the change over series relayl 6 and the releaserelay 5 inseries.v Slow-to-release relay 5,. upon energizing vover the vabovetraced circuit, connects,

ground to the release, conductor 22 at armature 36.; saidV groundcompletingav holding circuit for maintainingthe calling lineswitch inanoperated position and, in addition, makes the trunk line to the, con-lnecter H busy to all other lineswitches having access thereto; atarmature 37 and its Working contact prepares the circuit for thevertical magnet 13, and at itsresting contact opens a point in therelease circuit; and at armature 351prepares a lockingy circuit for ringcut-off relay 7 and switching relay l1. Y

Sloweto-release change over relayV 6, upon energizing over the abovetraced circuit, closes a circuitV at armature 39 for' maintaining itselfin operated position during the vertical impulses; at armaturedisconnects the rotary seriesrelay 10 and theV rotary magnet 14'at itsresting contact and at its workingA contact prepares a circuit foroperating vertical magnetv 13. In ad- Y dition, relay 6 at armature 38disconnects 'ground from the lower winding ol" relay 4 and substitutesthe normally grounded dial toneV vconductor 25 therefor. Responsive tothe connection of dial vtone 'to the lower winding of line relay 4 anaudible tone is v transmitted to the calling subscriber' `over thecircuit :previously'traced for the line Vrelay v4. `When the callingsubscriber hears 'the Vdial tonel he will proceed to dial the calledsubscribers telephone number.V a Thecalling subscriber may nowmanipulate the callin@ devicein accordance withthe digits in' thertelephone number of the desired called subscriber.'` Due to theoperation of the calling' device by the calling subscriber, the'circuitof the line relay `4 is 'interrupted a plurality of times in the wellknown manner and the line relay -responding to thesecircuit"interruptions, deenergizes a like .number yoit times. lllachltime.V Vline Arelay V4 deenergizesa vcircuit is closed or energizingthe change-'over relay A6 and Y vertical magnet 13 as follows: fromground by way voit armature 34 in its resting contact, Varmature 37 andits working lcontact vand armature 39 `for `maintaining slow-toreleaserelay v"6 in energized positionand by way of armature 40 vand itsvworkinggcon- 'tact to vertical magnet 13. By the opera- [tion of theverticalV magnet 13, the switch shaft and wipers are raised until thewipers '60, 61 and `(52 areopposite vthe desired levelv of bank contactsyinwhich the line conduc-A tors of ythe called line terminate. As :soonasV theA switch steps off-normal, oli-normal contacts 56 close therebyshorting the upper winding of the 'changefover relay 6. This relay,being slow `acting is maintained energized during thevertiical impulsesby way of its lower winding as previously described. After thetermination ofV the vertical impulses, line relay 4 energizes and opensthe circuit `for maintaining the change-over re- 'lay Genergized,whereupon said relay re- ',leases after an interval.vChange-over relay 6, upon `deenergiz'ing, at armature 38 substitutesdirect ground for conductor 25; and

at the resting contact of armature 40 pre-V pares a circuit for therotary magnet 14 and at its working contact opens the Vcircuit of thevertical magnet.

The calling subscriber may nowV dial the last digit of the callednumber. 'In response 'to the operation` of the Vcalling Vdevice by thecalling subscriber, the circuit for the.

the switch wipers are rotated step-by-step n and are finally broughttores't in engagement with the particular set or contacts in which theline of substation A is terminated, these contacts being indicated inthedrawings by reference characters 70, 71, and 7 2. The slow acting relay10 is energized in multiple with the rotary magnet and maintains itsarmatures attracted throughout Vthe rotarymovement. At armature 50series relay 1G opens the circuit orp switching relay 11 and prepares acircuit including, the busy relay '8 for testing the called line, and atarmature 51 maintains its own circuit and the circuit or" the rotarymagnet 14 independent of armature 45. necter H now depends upon whetherthe called line is busy or not. .Y

ltrwill now bejassuined that the Vline of substation A is busy whencalled. Under `these circumstances there will be a ground potential uponthe contact 72 and when-the ytest wiper 62 'comesto rest 1n engagementtherewith the busy relay 3 will be energized.`

over a circuit as follows: ground on test contact `72,.test wiper G2,armature 50-and its working contact, armature 47,`and winding 'of busyrelay 8 to battery. Shortly after the impulses cease, slow acting series'relay` 10 deenergizes and completes a locl.

ing circuit for the busy relay as follows:

rlhe operation of the conv ground by way of grounded release trunkconductorV 22, armature 44a-nd its working contact, normally closedsprings controlledv by armature 50, armature 47 ,and winding of busyrelay 8 to battery. kBusy relay 8, upon energizing, at armature 45opens'the circuit of the rotary magnet 14, and vat armature 46 connectsthe busy tone to conductor 21. The calling subscriber is now given the'busy tone in the well known manner.

lVhen the calling subscriber hears the well known busy tone, he willreplace his receiver thereby opening the circuit of line-l relay 4. Atarmature S4 and its working contact .line relay4 opens the Vcircuit ofslow-to-release relay 5 which thereupondeenergizes,.and at arinature-34and its rest-l ing contact prepares a circuit for energizing the.release magnet 12. v Slow-to-release' relay 5, upon deenergizing,.atjarmature .36 removes ground from the' release trunk conductor 22`thereby permitting therelease o-f the callingflineswtch and .by theremoval yof ground from the release trunk conductor 22the lockingcircuit of the busy relay 8 is opened whereupon said relay deener-'gizea v. At armature 37 and its resting conf tact release relay 5closes a circuit for. energizing the releasejmagnet 12 as follows:ground by way of armature x84 and its rest ing contact, a '1mature4 374and its resting contact, armature 38, off-normal springs 57,

and the winding of the release magnet 12 tobattery. The release magnet12 energizes over the: above traced" circuit and restores theswitchwipers-to theirnorinal position after vwhich the od-'normal springs 57open the circuit of the4v release magnet 12 in the usual. manner. l All"the apparatus used to vextend the connection are in normal posif tionand may be used for .other calls.

Having explained y. what occurs ywhen Ythe calledline is busy, it willnow be assumed tl'iatA the' calledjline isI idle. Suchbeing` the case,when 'the .test wiper l62 comes to liest in engagement withfa testcontact 72, it

Y will find no ground potential and the busy relay 8 will not beenergized. Instead, when the. slow; acting relayy lOffalls back, avcircuit isl closedthrougli ,the lower winding of the switching relay 11as follows.:v from ground by way ofnarniature l36,armature 44 anditsxresting contact, lowerwinding of `switching relay l1, resting`contact of armature 50. and 'saidparinature, wiperr 62, bank .cont`act`,72,. conductor.Y 4,` winding of cutoilrelay 76, and '.windingof, magnet81-to battery. Uponfthe closure ofthe above traced circuit :thevcut-lofi .relay 7 6 .of the r`lineswitch, LS roperates to.` clearftheline yof the.v substation A- from lits normal' batterygrciindjconiiections 'in 'the lineswitch LS.. Because of. 'the wellknown mechanical 1 interlocking arrangement vof the rotarylineswitclrthe wiper-sofrk the lineswitch areV .net ccnnected up.attliis time. In practice, due to yfaulty adjustment vof the, .cut-off4relayfit maylpull up a-trifle slowly with the result thatifringingcurrent.isfat once Aapplied to: the calledline the line". relayVwill flutter momentarily. Inorder to vercoine' tliis,f.ringi ng relay`9l has been added -inthe connector which haslitsenergizing circuit.closed whenr fthezswitching'relay is fully ',Operatedl.,Theinterval oftime that ity takes 'Y fthe' switclfiingv relay and then the .ringingrelay.: to. energize yissufficient to, enable the v.cujt-Aorelay .tobefully. operated before the ving beencorn'plete'd, ysubscribers mayIconverse 'as desired.

ringing relay applies ringing current to the line.v i

vThe switching relay 11, upon energizing,

closes at armature 53 a locking circuitfor relay Sand at armatures 48and 49 connects current to the line conductors ofthe ringing H forringing the called subscribconnecter er A.v The ringing circuitmaybetraced as y follows: .interrupted generator Int. Gen., armature 48,lowerwinding ofring cut-oil? relay' 7, resting contact 'of armature 41and subscriberls line conductor 73,the bridged ringerand condenser atsubstation A., sub- 9e said armature,`wiper "60, bank contactk 70,

scribers line conductor 75, bank contactj71,

wiper l61, armature 43 and its resting contact, armature l49 Ianditsworking contact, andy resistance R lto battery. Ringfback tone isconnected tothe calling subscriber by way of armature 58 in theusualmanner.

When the calledV subscriberl answers, the ring cut-oil' relay ture 42completes a by way of armature. At armatures 41 and 43`relay 7disconnects ringing current fromthe called lineand completes the talkingcircuit b etween'thecalling and called subscribers, and in. addition,-coinpletes ya .circuit for energizing the backbridge relay 3iveifivthe1v called subscribers'loop; Back :bridge relay 3,'up'onenergizing', 4reverses 4the flowV of 'current'to lineA at 'armatures thel'calling subscriberfs 31 and 32',.at armature 130,*connects ground. tothe conductor 59 for 100V f 7 energizes Vand atarmalocking'circuit for`itself f maintainingy relaysj7 andf 1lji operated,

at armature '33 opens the circuitjto the revhangs up. Y The .reversal ofcurrentl to ythe vcalling line rvmay be used fori yoperating `a meterif'desired. Theconneetion now hay'- tlie replacement of thereceiveribythe kcalling subscribenthe circuit of opened and i said 'A relaydeenergizesf armature34 line 'relay4 opens' the,circuit ofslow/to-rel'easeIk vrelay After'the'conversation and responsive to ..125'Y 'line relay 41s I .At

5 andfinaddition yprepares a circuit 'for operating the rel a se A .115lease niagnetso thaty `the connecter switch cannot release kuntil 4the'called subscriber.

the Ycalling and ca11ed t..

with each einer.

VIVto magnet 12. After the interval for which it is adjustedslow-to-release relay 5 deenergizes' and at armature 36 removes groundfromv release conductor 22. e' After Vthe line ce Ui i trunk conductor22.

relayt deenergizes and before slow-to-release relay deenergizes Vacircuit is closed for operating the rotary seriesrelay as follows:ground by wayof armature Saand its resting contact, armature 37 and itswork- Y ing contact, armature :1l-.O and its resting contact, restingcontactfof armatureY l5 and said armature, and winding oi relay 10 tobattery. lRelay 10,"upon energizing, at armature removes the groundextending byrway of armature 52v and the lower windingoiv'switchingrelay ll from the release trunlrconductorf22 so that whenthe release ture 37 and its working contact opens the circuit ofthelseries relay l0 andV at armature 37 and its resting contact preparesa circuit for the release magnet l2 which circuit,`however, isropen atarmature 33. After the interval. for ywhich it is adjusted 'relay l0releases and at armature 50 completesthe following circuit formaintaining the connector H` busy until the called man hangs up; groundby way of armature 52, armature 50 and its' resting contact, lowerwinding-of switching relay lil, resting contact of armature 44 and saidarmature, 'to release When the called subscriber AV replaces hisreceiver the circuitV of theback bridge relay 3 is opened at thesubstationwliereupon said relayv releases. vRelay 3, upon deenergizing,

. at armature 30 opens vthe locking circuits of the `ring cut-oil relay7 and the switching f relayll whereupon-the latter relays release.'r-I"he,switcliing relay'at armature '54 opens the-circuit of. theringing-,relay 9, whereupon saidrelay releases. At armatur 33back'bridge lrelay Vcompletes 'the circuit.

for vthe release magnet Vi12 which thereupon energizes`and restores theswitch to normal in the same mannerk Vas previously described.

:RespQll'sive'tothe deenergizati'on of switching relay ll'the circuitfor the cut-off relay 7' 6 `lof the lineswitch LS is opened at varmature52.` whereupon y"said cut-oil`A relayfre- Y leases in the usual manner.All of. theapparatus used inzfestablishing theq'connection is l*now innormal position fand may be usedffor extending other calls.

V'In casethe called subscribenis: the Vfirst `to replace hisreceiyer'the backf'bridg'e relay 3 would deenergize and the switchVwould be yheld inoperated position until the calling subscriber hung upwhereupon theline and.'

13eme/i release relays would deenergize and complete the circuit forrestoring the connecter to normal position.

` Having described my invention, what I v pointed out with, a connecterswitch for: connecting'` ith said line through saidgnormal conduc-c.tors, a line switch individual to said line for extending a lconnectiontherefrom, a

line relay in said line switch normally con-` nected to said normalconductors, a cut-off relay in'said lineswitch adapted when enfvergizedto disconnect said line relay from said normal conductors,'a switchingrelay in said connecter, a ringingre'lay in .said connecter adapted whenvenergized, to `connect ringing current to said normal Vconductors,means VJfor closing an energizing circuit for said switching and cut-offrelays in series, and contacts on said switching relay'for closing anVenergizing circuit for said ringing relay. f

2. ln a connecter switch for use in telephone systems, a ring-cut-offrelay, a pair of" line wipers permanently connected to contacts on saidring cut-off relay, a switching relay, a ringing relay, Ymeansforenergi'zing Vsaid Vswitching relay, yand contacts on saidswitchingrelay for closing an energizing circuit for saidy ringingrelay," to

cause' said ringing relay-Y to energize and.

apply ringing currentto said line wipers.

- In a telephone system, means including ioo 'a' two digit vertical randrotaryconnecterj switch for completing a connection from a callingV to acalledV subscribers'line, means said connecter switch, a relay'insaidcon- 'necter energized responsive to said eXtension, and contacts onsaid relayk for con- *responsive to Vthe initiation of a call by.acalling subscriber for extendingk his lineto i'io Y trolling theVconnection andI disconnection. y

of dial tone to the callingsubscribersiline.`

ing a two-digit ,vertical and rotary connecter switch for completing aconnection from 4.' In a telephone'systern, VAmeans includi'i5V acalling to a called subscribers'V line, means responsive to theinitiation of acall by aV calling subseriber for extending his line to g.i

said Vconnecter switch,"k axvertical and 'ro tarychange-overy relayA insaid yconnecter' switch energized responsive to rvsaid `eXten- 'sion anddeenergized .responsiveto the cessation o'ftlie'calling of the'first-digit of the desirf-idv number, and contacts V0n said relay forconnecting anddiscon'necting a' distinctive tone to thecallingrsubscribers line.

5. Ina telephonejsystem, artwo-digit'con-r k130 necter switchhaving adirectively controlled circuiting said relay repsonsive line, achange-over relay iii said connecter for controlling the change-overfrom the vertical to the rotary movement, means for kenergizing saidrelay when the connecter isseized, separate meansl for maintaining saidrelay energized during the vertical movement after which said relaydeenergizes, and means controlled by 'said relay for connecting anddisconnecting dial tone to the calling line responsive to the energizedand deenergized positions, respectively, of said relay. y c

6.111 a telephone system, a two-digit connecter switch having adirectively controlled vertical movement anda directively con@ trolledrotary movement for completing a.

connection from a calling to a called subscribers line, a change-overrelay in said connecter for controlling the changeover from the verticalto the rotary movement, an energizing circuit forsaid relay closedresponsive to the seizure of said switch, meansv for short-circuitingsaid relay responsive to the irstvertical movement of said switch,separate means for maintain'- ing said relay energized during thevertical movement after which it deenergizes, and contacts on said relayfor connecting dial tone to the calling liney only duringy the time saidrelay is energized'.

7. 'In a telephone system, va two-digit connecter switch having adirectively controlled ing a twomotion automatic switch for exverti'calmovement and a directively controlled rotary movement for completing aconnection, a changeover vrelay in said connecter for controlling thechange-over froml the vertical to theirotary movement, means forenergizing said relay; means for short to the4 rst vertical movementofthe connecter, and sep- I aiate means for maintaining said relayenergized during the vertical movement after which it deen'ergizes.r 'Y

8. Ina telephone system, a two-digit verti cal and rotary connecterswitch, a changefV over relay in said switch, off-normal springs in saidswitch normally l open while the switch is innormal position and closedwhile the-switch is-inoif-normal position, as energizing circuit forsaid relay including a winding on said relay,means for-closing saidcircuit responsive `to f the seizure of. said switch to energize saidrelay over said winding, means responsive to the iirstV verticalmovement of said switchfor operating said off normal springsVY to shortcircuit said winding, and a second winding on said relay lformaintaining ksaid relay energized until after the vertical movement.

in said switch normally open while the switch is in normal position andclosed while the switch is in olf-normal position, an energizing circuitfor said relay including a winding on said relay, means for closing saidcircuit responsive to seizure of said switch to energize said relay oversaid winding, means responsive. to the first vertical movement of saidswitch for. operating said oflj normal springs to short circuit saidwinding, and means controlled by said relay yfor maintaining itself inenergized vposition until after the vertical movement.

10. Inl a telephone system, a two-digit vertical and rotary connecterswitch, ay

change-over relay in said switch, meansV forl venergizingy said relayresponsive to the seizure of said switch, means for rendering said firstmeans ineffective after the first vertical movementof the switch, andseparate means exclusive 'of said first mea-ns for maintaining saidrelay' energized until after the vertical `movement of the switch.

eol

1l. In a telephone system, a two-digit*` vertical and rotary connecterswitch, a change-over relay in said switch having two windings, meansfor initially energizing said relay over its first winding, means forvrendering said iirst winding ineffective to energize said relay afterthe rst vertical movement of the switch, and means for subse quentlymaintaining said relay energized over its second winding` until afterthe verticalmovement. y

Q12. 1n a telephone system,.means includ-A Y' tending a connection froma calling line, -meaiis responsive to the initiation of a call by acalling subscriber vfor. extending -his line to said switch, and means`in said switch operated responsive to said extension for transmitting adistinctive tone toiiidi'cate rto .the calling subscriber that he mayproceed with the 'call and effective upon completion of the firstmovement ofsaid switch to disvconnect said tone before the second1iiove-' ment of said switchbegins. n y

In witness whereof, l hereunto subscribe my name thislllth day ofSeptember, A. D.,

'CLARENCE E. LOMAX.

' 9. In a' telephone system,` a twosdigit verti-f`v cal and rotaryconnecter switch, achangef over relay insaid switch, off-,normal springsiio

